Crank shaft and method of balancing the same



A Aug. 28, 1923.

i,466.446 BRUsHlf l CRANK, SHAFT AND METHOD 0F BALANCING- THE SAME K Y Filed'march 26. 1921 Passed eng. ze. 192e. D 1 Mettete' sra-iras earner estres;

Lawson r. Bauen, or nnraorr, rrionreeii.

'os-ANR SHAFT Ann atari-*ron 'orBaLANcING 'man SAME.

Appiiation med March 2s, 1921'. serial No. 455,724.

To @ZZ whom 'it may concern', o, the portions B ofthefshaft by the portions -Be it known that I, ALA'NsoN B.- BRUSH, D and D extending in the same radial a. citizen. of the United States 'of `America, plane.

residing at Detroit', in the county of `Wayne The pins C and C are connected with pins and State 'of Michigan, have invented cer- E and E in a different radial plane'by the @o tain new andV useful mp'revements "in Crank obliquely extending portions F and F. The.

Shafts and VMethods of Balancing the Same, pins E and E` are connected with the pins of which the following is a specification, G and G in the third radial plane` by obreferen'ce; being had therein to the accornliquely-extendingl oortions Yl-I and .H and l panying draw-ings.` between the pins and G" isa portion I 05 The invention relates to crank shafts for having y,a projecting lug J for the attachmulti-cylinder engines which are provided ment of a center counterbalancing weight. with more than four aligned cylinders, and All ofthe pins and all of the crank throwsV it is the object of the invention to obtain a areA hollow, communicating with each' other,

construction which may be used with a sinand are connected at the opposite ends of 70 gle `pair 'of shaft bearings, or, in other the shaft with channels K kleading tothe words, dispensing with all bearings linterjournals B and B for the main 1eearings, y mediate the ends of the shafts. In the pre'sthe arrangement being such that lubricant ent state of the art it is not considered praccan be fed through the entire shaft in suf- 2U tical to build crank shafts of more than four cient volume and at sufficient speed to ab- 75 throws without one or more intermediate sorb the heat lfrom the pins due to the fricbearings. rhis is for the reason that the tion of the bearings thereon. bending inom'ent on the shaft is increased To balance the shaft a center counter-balwit'h the added number of throws, requiring Y ancing weight L is secured to the lug J by an enlargement of the shaft to stien the means of a shank M threaded at its ends and 80 same, while this enlargement of the shaft inengaging a correspondingly threaded apercreases the friction on the crank pin bearture in the lug J. This threaded engageings, and consequently, the heating effect ment permits of lengthening or shortening and danger of burning out said bearings. the shank M in its relation to the lug J by' SH wWith my improved construction the shaft revolving the counter weight, which facilise is properly stiifened by enlargement of the` tates the operationof obtaining a rough diameter thereof and to avoid increasing the balance. A more accurate balance may then heat, a cooling medium is passed continu be obtained by adding or subtracting weight ously through the shaft to lower the temyfrom the member L. The opposite ends of perature of the bearings. I have also prothe shaft are also provided with countero0 vided a construction which is accurate in balancing weights which function in codynamic and static balance, so that only end operation with the center counterbalance bearings are necessary and the length of the to bring the shaft as a whole in balance structure can be condensed by the omission about the axis of Ythe mainv bearings. Y

l rlhese last-mentioned ycounterweights N are 95 Y fil 4o of all intermediate bearings.

In the drawings; V Y( secured to bearing faces O o-n the throws Figure l is a sectional side elevation of and D. The weights N are, as shown, sethe 'crank shaft; cured by center bolts P and are additionally Figure 2 is a cross-section uponline 24-2 held from displacement by tonguesQg'wlrich of Fig. l; engage grooves R in the faces O. 10o

Figure 3 is a cross-section on line 3-3 of `With the shaft constructed as described Fig. l. Y the Yincreased rigidity obtained vby enlarge- A is the crank shaft having the end jourment in diameter is sutiicient to safely take nal portions B and B and intermediate the care of increased bending moment due to the same a plurality of crank throws for more elimination of all center bearings, while the 105 than four aligned cylinders. As specifically increased frictionally developed heat in the shown, there are six throws arranged in enlarged pin bearings is absorbed by the three different radial planes. rJlhese include cooling medium circulating through the the crank pins C and C, which are adjacent shaft. rTherefore, the single pair of shaftto the end bearings and are connected with supporting ournal bearings arranged at op- 11o posite ends thereof are VsuificientV and the constructionof the Ymotor is simplified and condensed. Y

"What l claim as my invention is: l. A crank shaft for internal combustion engines, comprising journalV hearings at opposite ends only, six intermediate Crank pins .arranged in substantially axially aligned pairs in three radial planes, and throws directl connectinxr said ins with each other andisaid end journal bearings.V 'Y

2. A crank sha-ft Afor internal combustion engines, comprising journal bearings at oparranged in substantially axially alignedV pairs in three radial planes and throws di rectly connecting said pins with each other and said journal bearings, said pins being increased in diameter over' that required for i rigidity with a. less number of throws,V and means forabsorbing the increased heat incident to the enlargement of the pins.

4L. A crank vshaft for internal combustion engines comprising journal hearings at opposite ends only, siX intermediate crank pins y arranged in substantially Vaxially aligned pairs in three radial planes and throws directly connecting said pins with each other and said journalfbearings, said pinsand throws being hollow to form a continuous channel from end to end of the shaft and being enlarged to impart added rigidity over Vthat required for a less number of throws,

said channelY permitting the passing of a cooling medium through'the shaft to absorbthe added frictional heat incident to theV increased size of the pins.

5. A crank shalt for internal combustion engines comprising journal bearings at opposite ends only, six intermediate crank pinsV arranged in substantially` axially aligned pairs in three radial planes, and throws directly connecting said pins to each other and Vsaid journal bearings, said pins and throwsV being hollow to forma continuous channel from end to end of the shaft for the passageV of a cooling medium and being increased in diameter over that required for a less number of throws to secure rigidity, a counterweight at the middle of said shaft, a pair of counterweights atthe ends of said shaft,

said middle countei'weio'ht having its center' of gravity lying in Vone plane passing through the aX-is of the shaft, and Vsaid end counterweights having their Centers of gravity lying in another plane passing throughthe axis of said shaft. Y

ln testimony whereof I ai'lix my signature.

ALANSON P.' BRUSH. 

